booleon algebra Flashcards
What is a half adder
It is a circuit that is able to take a two bit input and produce a two bit output, which is the correct result of a binary addition of the two inputs
summarise a full adder
- two half adders combined
- can add 3 bit inputs rather than 2
- two half adders joined together with an extra OR gate to output the carry bit
a + 1
1
a and 0
0
a + 0
a
a and 1
a
a + a
a
a and a
a
a or not a
1
a and not a
0
not not a
a
a or a
a
1 and not B
not B
commutative law
values in AND or OR expressions can be swapped without changing the result
eg X.Y = Y.X
Distributive law
a value outside a set of brackets can be distributed between the values in the brackets
- eg X.(Y+Z) = X.Y + X.Z
associative law
- the order of operators in an expression has no impact on the result
- eg : (X+Y) + Z = X + (Y + Z)
why do we use de morgan’s law
- reduces cost as only one type of gate is required
what is a d type flip flop used for
Used to store state (of data input) // used as a memory (unit);
One input to a D-type flip-flop is a data signal.
State what the other input to a D-type flip-flop is and what it is used for
Input is: Clock / trigger / enable;
Used For: State of data input is stored // output is updated to reflect current status of
input;
